转自：http://blog.csdn.net/hunanwy/article/details/8563090
Ti，called from the input thread. Input thread负责分发input event到window.
Tq，called from the low-level input queue thread. Input queue thread负责将raw input event放到global input queue，Ti thread会读出global input queue.
Lw，called with the main window manager lock held. 在Lw可以调用package mgr, power mgr. 但不能调用activity mgr和其它大多数services。
Li，called with the input thread lock held.比Lw更加苛刻.
Lp，for an internal lock of the PhoneWindowManager. This is used to protect some internal state, and can be acquired with either thw Lw and Li lock held, so has the restrictions of both of those when held. (ref PhoneWindowManger.java)